i965/miptree: Remove redundant check for null texture
i965/miptree: Remove redundant check for null texture

There exact same check earlier in brw_miptree_layout() which
intel_miptree_create_layout() in turn calls unconditionally.

Reviewed-by: Samuel Iglesias Gons\341lvez <b753b212f30aed827c3eea2e437609dc37310153@igalia.com>
Reviewed-by: Jason Ekstrand <68c46a606457643eab92053c1c05574abb26f861@jlekstrand.net>
Signed-off-by: Topi Pohjolainen <749697f19798b7f640b17221fd283b903825f071@intel.com>

metora/MesaGLSLCompiler,metora/MesaGLSLCompiler,metora/MesaGLSLCompiler